Part I
In 1935, T. E. Lawrence dies in a motorcycle accident. His memorial service is held at St Paul's Cathedral.
During the First World War, Lawrence is a misfit British Army lieutenant, notable for his insolence and education. Over the objections of General Murray, Mr. Dryden of the Arab Bureau sends him to assess the prospects of Prince Faisal in his revolt against the Turks. On the journey, his Bedouin guide Tafas is killed by Sherif Ali ibn el Kharish for drinking from his well without permission. Lawrence later meets Colonel Brighton, who orders him to keep quiet, make his assessment, and leave. Lawrence ignores Brighton's orders when he meets Faisal; his outspokenness piques the prince's interest.
Brighton advises Faisal to retreat after a major defeat, but Lawrence conceives a surprise attack on Aqaba, whose capture would provide a port from which the British could offload much-needed supplies. To do this, he convinces Faisal to provide fifty men, led by a pessimistic Sherif Ali. The teenage orphans Daud and Farraj attach themselves to Lawrence as servants. With difficulties, they cross the Nefud Desert and travel without rest on the last stage to reach water. An Arab named Gasim succumbs to fatigue and falls off his camel unnoticed during the night. When Lawrence discovers Gasim missing, he turns back and rescues him. The men are won over.
Lawrence persuades Auda Abu Tayi, the leader of the local Howeitat tribe, to turn against the Turks. Lawrence's scheme is almost derailed when one of Ali's men kills one of Auda's men because of a blood feud. Since retaliation by the Howeitat would shatter the alliance, Lawrence announces he will execute the murderer himself. Lawrence is stunned to discover that the culprit is Gasim but shoots him anyway.
The next morning, the Arabs overrun the Turkish garrison. Lawrence heads to Cairo with Daud and Farraj to inform Dryden and the new commander, General Allenby, of his victory. While crossing the Sinai Desert, Daud dies after stumbling into quicksand. Although Lawrence's report of Aqaba's capture is initially disbelieved, he is promoted to major and given arms and money for the Arabs. Lawrence asks Allenby whether there is any basis for the Arabs' suspicions that the British have designs on Arabia. Allenby states that the British government has no such designs.
Part II
Lawrence launches a guerrilla war by blowing up the Ottoman Hejaz railway between Damascus and Medina and harassing the Turks. An American war correspondent, Jackson Bentley, publicises Lawrence's exploits and makes him famous. On one raid, Farraj is badly injured. Unwilling to leave Farraj to be tortured by the enemy, Lawrence shoots him dead and flees.
When Lawrence scouts the enemy-held city of Deraa with Ali, he is taken along with several Arab residents to the Turkish Bey. Lawrence is stripped, ogled, and prodded. For striking out at the Bey, Lawrence is flogged and thrown into the street, where Ali comes to his aid. The experience leaves Lawrence shaken. He returns to British headquarters in Cairo but does not fit in.
In Jerusalem, General Allenby urges him to support the "big push" on Damascus. Lawrence reluctantly returns.
He recruits an army that is motivated more by money than by the Arab cause. They sight a column of retreating Turkish soldiers who have just massacred the residents of Tafas. One of Lawrence's men is from Tafas and demands, "No prisoners!" When Lawrence hesitates, the man charges alone and is killed. Lawrence takes up the dead man's battle cry; the result is a slaughter in which Lawrence participates, despite Ali's protests.
Lawrence's men take Damascus ahead of Allenby's forces. The Arabs set up a council to administer the city, but the British cut off access to the public utilities, leaving the desert tribesmen to debate how to maintain the occupation. Despite Lawrence's efforts, the Arab leaders bicker constantly and soon abandon most of the city to the British.
Lawrence is promoted to colonel and ordered back to Britain, as his usefulness to both Faisal and the British is at an end. As he leaves the city, he looks longingly at the departing Arabs before his car is passed by a motorcyclist, who leaves a trail of dust in his wake.
